I would like to subtract two columns - create_time and update_time of 'timestamp without time zone' type and then order results based on subtraction-result (time interval). I checked http://www.postgresql.org/docs/current/static/functions-datetime.html , however these examples didn't work with actual column values. e.g.something like:
'select epoch (update_time) - epoch (create_time) AS Column1 from users order by Column1; '
Any hints or documentation liks will be really nice. Thanks.
